Humans have been tied to coastlines since the first primitive societies were established thousands of years ago. Before airplanes, trains, and cars, many people travelled by sea. Today, more than 600 million people across the globe live in coastal areas that are less than 30 feet above sea level, and about 33 percent of the world’s largest cities are located in these coastal areas, just like us here in Boston. This same habitat is also extremely critical to hundreds of thousands of animal species—from snails to crabs to turtles to penguins to seals… the list goes on and on!

King tide seeps up the storm drains on Long Wharf

Our coastlines have long been shaped by our tides, which ebb and flow and shape our land. What many people don’t realize is that since the mid-19th century, our coastlines have also been changing as sea levels have been rising as a result of climate change. When we burn fossil fuels like coal and oil and gas, it releases carbon dioxide which creates a blanket around the earth, trapping in the earth’s heat and warming our planet and our seas.

High tides lap over the Harbor Walk on Long Wharf

In addition to melting land ice, a big contributor to sea level rise is that, like air and other fluids, water expands as its temperature increases. The faster water molecules move, the more space they take up. Think about people at a school dance; when you’re slow dancing, you don’t more around too much, and don’t take up as much space on the dance floor. When a faster tempo song is on, dance moves start getting crazier and bigger, and you need more space to bust a move! Water molecules move the same way. Here’s a great visualization of that phenomenon. As climate change increases the ocean’s temperature, the water will expand, contributing to sea level rise due to thermal expansion.

The consequences of sea level rise became all to real for many communities during the recent king tides and super moon tides. These tides are much higher than normal due to the moon’s proximity to Earth and its natural gravitational pull. Here in our own back yard, the water spilled over the Harbor Walk on Long Wharf. Now imagine if winds or a storm surge pushed even more water into Boston Harbor!

Long Wharf's Harbor Walk underwater

The good news is that we have the ability to slow down the rate of sea level rise. By talking about climate change and sea level rise with our friends and families, and adding our voice to existing community efforts, we can continue to spread an impetus for change. The City of Boston has already instituted new building codes for new development on the waterfront — instead of keeping electrical equipment in the basement, new structures will put them on the roof!

The Aquarium has been speaking to visitors and working with other science educators about climate change and sea level rise, inspiring people to join their communities in taking steps to slow climate change. As American citizens, we have the power and responsibility to vote for people and policies that support renewable energy, so that we can keep our ocean and planet healthy for future generations. Explore some of the resources available on our website. How can you get involved to help keep our coastlines protected?

Aquarium staffer splashes through high tide along Harbor Walk on Long Wharf